Total beginner - first scope

[Neil H]

Hi I would watch some of these videos which will help you top guy 

 

[Second Time Around]

I had the same dilemna as you with my grandkids who live in London and chose a Starsense Explorer scope.

This is because in my experience the single biggest reason that beginners give up astronomy is that they can't find objects.  This is even more so from cities where relatively few stars are visible to help.  Starsense Explorer makes this incredibly easy.

It doesn't have tracking, but if you lose the object it's very quick and easy to re-find it - much easier than without Starsense Explorer.

It also gives you a list of the best objects for the night that you're observing, including those that are rewarding from cities.  At the the push of a button Starsense Explorer will even tell you a lot about the objects - youngsters in particular love this.

The whole process is very intuitive - my 8 year old picked it up immediately and was soon controlling everything himself.

I chose the least expensive in the range, the 70mm f/10 refractor.  Even though the next size up, the 80mm, is currently on special offer, I'd still go for the 70mm at £169.  This is because it has a wider field of view plus, as the mount is the same on both models, it's steadier.

I did upgrade some of the accessories.  I bought a much better quality Celestron diagonal.  (£45 from First Light Optics).  There are cheaper ones, but this gives a very good price/performance ratio.  The diagonal supplied with the scope isn't that good but has the advantage of a correctly orientated view for terrestrial use such as birdwatching and holidays.  This is one of the benefits of choosing a refractor.

Next I'd suggest a zoom eyepiece.  I find youngsters in particular love zoom eyepieces.  My 8 year old said it was like landing on the moon!  It also helps with tracking because if you lose an object at high power you can just quickly zoom out and it'll probably then still be in the field of view.  I chose a 9-27mm as it gives a particularly useful range of magnifications on this f/10 scope.  Those from SvBony usually cost about £50 but are often (now for instance) on special offer at about £40.

I also bought a better quality 2x Barlow lens (£27 from First Light Optics).  This is the type where the bottom black section can be unscrewed and then screwed into the filter thread of an eyepiece.  This gives an additional amplification factor of about 1.5x, and so triples the range of magnifications at very low cost.

Finally, but this could come later, I'd suggest a 32mm Plossl (£29 from First Light Optics).  This gives the maximum field of view possible with this scope of approx 2.25 degrees (the full moon is 0.5 degrees in diameter).  This gives plenty of space around the Pleiades to see their full beauty - the 1.6 degree field of view with the 80mm f/12.5 doesn't.

One final thought about the Starsense Explorer units is that a very simple modification means that you can move them to different telescopes where they fit into a standard finder shoe.  If as is likely you buy other scopes in the future this is a huge plus.  If on the other hand you don't get hooked on stargazing then the 70mm Starsense Explorer will be extremely easy to sell for a good price.

In fact, I was so impressed with the 70mm Starsense Explorer that I bought another for myself and did just that modification myself!

Edited August 6, 2023 by Second Time Around

[Mandy D]

@Second Time Around I like the ideas you have presented, here. I have just bought a 300PDS OTA and am shortly going to be building a Dobsonian base for it and was looking for easy ways to orient it on the sky - inclinometer, digital compass, etc, but this idea would make it much simpler and potentially cheaper. How does the Skysense cope at longer focal lengths? Native would be 1500 mm, but barlowed I would go to 3 or 4.5 m. Does it locate the outer two gas giants well?

A while ago I was looking for an inexpensive 70 mm refractor and have now bought a 100 mm, f/10, so 700 mm focal length would fit in nicely with my existing kit, whereas the 80 mm would be that bit too long to offer any benefit beyond portability. What is the chromatic aberration like in the 70?

Sorry for asking so many questions, but this is my final one (for now!). What is involved in the modification to mount this device in a finder shoe?

[Zermelo]

24 minutes ago, Mandy D said:

What is involved in the modification to mount this device in a finder shoe?

 

 

[Second Time Around]

On 05/08/2023 at 16:20, Mandy D said:

@Second Time Around I like the ideas you have presented, here. I have just bought a 300PDS OTA and am shortly going to be building a Dobsonian base for it and was looking for easy ways to orient it on the sky - inclinometer, digital compass, etc, but this idea would make it much simpler and potentially cheaper. How does the Skysense cope at longer focal lengths? Native would be 1500 mm, but barlowed I would go to 3 or 4.5 m. Does it locate the outer two gas giants well?

A while ago I was looking for an inexpensive 70 mm refractor and have now bought a 100 mm, f/10, so 700 mm focal length would fit in nicely with my existing kit, whereas the 80 mm would be that bit too long to offer any benefit beyond portability. What is the chromatic aberration like in the 70?

Sorry for asking so many questions, but this is my final one (for now!). What is involved in the modification to mount this device in a finder shoe?

I use a 10 inch f/4.8 Dob and the lowest power on my 7.7-15.4mm zoom gives a field of view of 0.83 degrees.  Starsense Explorer has  never failed to get an object within this field of view.  So finding the outer planets is no problem.

It means that I have no need for a longer focal length as a "finder eyepiece" on this scope.

There is of course some chromatic aberration with the 70mm, but as the focal ratio is f/10 I find it acceptable even without a filter.  I'd add that the smaller the diameter of a scope the less the chromatic aberration for a given focal ratio.

To add to Zermolo's post, a search will throw up lots of threads on converting a Starsense Explorer unit.  If you have access to a 3D printer you may find this adapter of use: https://www.thingiverse.com/thing:4868065

Edited August 7, 2023 by Second Time Around

[bosun21]

I placed the Starsense unit from my 8” dobsonian to my 12” F5 1500mm FL. As previously stated the targets are always in my FOV with a 17.5 Morpheus.

[Mandy D]

43 minutes ago, Second Time Around said:

I use a 10 inch f/4.8 Dob and the lowest power on my 7.7-15.4mm zoom gives a field of view of 0.83 degrees.  Without a single exception Starsense Explorer has always got an object within this field of view.  So finding the outer planets is no problem.

It means that, unless I specifically want a larger exit pupil or an extra wide field of view, I have no need for a longer focal length eyepiece on this scope.

There is of course some chromatic aberration with the 70mm, but as the focal ratio is f/10 I find it acceptable even without a filter.

To add to Zermolo's post, a search will throw up lots of threads on converting a Starsense Explorer unit.  If you have access to a 3D printer you may find this adapter of use: https://www.thingiverse.com/thing:4868065

Thanks for that. I should have noted that I am imaging, but it looks like, worst case, I will have about 0.5° lateral FOV, so it should be OK most of the time.

Good to know that the CA on that little scope is acceptable. Filters are always an option if I were ever to use it for imaging, which would probably only be when travelling.

Thanks for the link. I don't have access to a 3D printer, but looking at the images, it all makes sense and I think I can buy a finderscope foot and machine a piece of aluminium for the base that the Starsense sits on and mate them together. This has been a huge help! It looks like yet another telescope will be added to the collection!

[Second Time Around]

Something else I'd like to highlight about Starsense Explorer is that, unlike many other systems, including digital setting circles and Go-To ones, the scope can be moved around the garden without having to be set up again.  This is because it doesn't need realigning.  Instead you simply go back to the same object if for instance it went behind a tree, or on to the next object.

This is one of the reasons I recently sold my (expensive) Nexus digital setting circles.  Starsense Explorer is also quicker at setting up in the first place.

Edited August 5, 2023 by Second Time Around
Added expensive

[Mandy D]

11 minutes ago, Second Time Around said:

Something else I'd like to highlight about Starsense Explorer is that, unlike many other systems, including digital setting circles and Go-To ones, the scope can be moved around the garden without having to be set up again.  This is because it doesn't need realigning.  Instead you simply go back to the same object if for instance it went behind a tree, or on to the next object.

This is one of the reasons I recently sold my Nexus digital setting circles.  Starsense Explorer is also quicker at setting up in the first place.

Being able to move without having to set up again is really quite handy as I have to do a lot of tree dodging in my garden.

[Second Time Around]

Thinking further about the upgrades to the 70mm Starsense Explorer I'd suggest the order of priority would be:

1) better diagonal

2) 9-27mm zoom eyepiece

3) 1.5/2x Barlow

4)  32mm Plossl

I'll change my original post to reflect this.

The reason I put the zoom eyepiece so high up is that it enables beginners to easily learn what difference a change of magnification makes on all the various classes of object. It also shows them what focal lengths would be most useful to their eyes, their telescope, and their observing conditions.  In fact, I always recommend that beginners start with a zoom eyepiece.

Additional, this zoom will be much better quality than the eyepieces supplied with the scope.

Edited August 6, 2023 by Second Time Around

[Dimitrisanagn]

19 hours ago, Second Time Around said:

I had the same dilemna as you with my grandkids who live in London and chose a Starsense Explorer scope.

This is because in my experience the single biggest reason that beginners give up astronomy is that they can't find objects.  This is even more so from cities where relatively few stars are visible to help.  Starsense Explorer makes this incredibly easy.

It doesn't have tracking, but if you lose the object it's very quick and easy to re-find it - much easier than without Starsense Explorer.

It also gives you a list of the best objects for the night that you're observing, including those that are rewarding from cities.  At the the push of a button Starsense Explorer will even tell you a lot about the objects - youngsters in particular love this.

The whole process is very intuitive - my 8 year old picked it up immediately and was soon controlling everything himself.

I chose the least expensive in the range, the 70mm f/10 refractor.  Even though the next size up, the 80mm, is currently on special offer, I'd still go for the 70mm at £169.  This is because it has a wider field of view plus, as the mount is the same on both models, it's steadier.

I did upgrade some of the accessories.  I bought a much better quality Celestron diagonal.  (£45 from First Light Optics).  There are cheaper ones, but this gives a very good price/performance ratio.  The diagonal supplied with the scope isn't that good but has the advantage of a correctly orientated view for terrestrial use such as birdwatching and holidays.  This is one of the benefits of choosing a refractor.

Next I'd suggest a zoom eyepiece.  I find youngsters in particular love zoom eyepieces.  My 8 year old said it was like landing on the moon!  It also helps with tracking because if you lose an object at high power you can just quickly zoom out and it'll probably then still be in the field of view.  I chose a 9-27mm as it gives a particularly useful range of magnifications on this f/10 scope.  Those from SvBony usually cost about £50 but are often (now for instance) on special offer at about £40.

I also bought a better quality 2x Barlow lens (£27 from First Light Optics).  This is the type where the bottom black section can be unscrewed and then screwed into the filter thread of an eyepiece.  This gives an additional amplification factor of about 1.5x, and so triples the range of magnifications at very low cost.

Finally, but this could come later, I'd suggest a 32mm Plossl (£29 from First Light Optics).  This gives the maximum field of view possible with this scope of approx 2.25 degrees (the full moon is 0.5 degrees in diameter).  This gives plenty of space around the Pleiades to see their full beauty - the 1.6 degree field of view with the 80mm f/12.5 doesn't.

One final thought about the Starsense Explorer units is that a very simple modification means that you can move them to different telescopes where they fit into a standard finder shoe.  If as is likely you buy other scopes in the future this is a huge plus.  If on the other hand you don't get hooked on stargazing then the 70mm Starsense Explorer will be extremely easy to sell for a good price.

In fact, I was so impressed with the 70mm Starsense Explorer that I bought another for myself and did just that modification myself!

Thank you for detailing your experience. Seems quite similar to what I will be facing!

How easy was the tracking experience for the little one?

Hearing that such a scope could have a rather wobbly mount, did you have to mostly resort back to Starsense in order to track planets or other objects back to the FOV, or was tracking not a real issue?

 

I think nebulae and other DSO will be tough to find in the city, but an easy and good look of planets and systems like the pleiades would be desirable.

 

[Second Time Around]

The mount is smooth enough to track by hand at low to medium powers.  If you do lose the object you can just refind it by touching the object on your phone screen and following the arrows.

However, with the zoom eyepiece you'll not have to do that often because, as I mentioned, you can just zoom out and almost certainly the object will then be in the field of view again.

I've now passed the scope (but not the Starsense Explorer unit) on to a couple of beginners.

Using the zoom at 9mm plus the 1.5x Barlow gives a magnification of 117x.  That's about the practical limit on this lightweight mount. Yes, you can go higher (I've gone to 150x), but the vibrations will take longer to settle.

In fact I seldom used the Barlow at 2x because 1.5x is more useful.  

As a broad generalisation, for most DSOs I used the zoom without the Barlow.  This gives 26-78x.

For the moon, planets and most double stars I used the zoom plus the 1.5x Barlow.  This gives 39-117x, although in practice I'd more often be using 78-117x.  

A further tip is that if you're looking for an equivalent focal length of say 6mm, you'll get a wider field of view with the zoom set at 9mm with a 1.5x Barlow compared with the zoom at 12mm and a 2x Barlow.  This is because most zooms have a wider apparent field of view at their lower focal lengths.

Edited August 6, 2023 by Second Time Around